Are you researching the US? If yes, the Bureau Of Labor statistics has this information: http://www.bls.gov/bls/proghome.htm#employment http://www.bls.gov/bls/p

Are you researching the US? If yes, the Bureau Of Labor statistics has this information: http://www.bls.gov/bls/proghome.htm#employment http://www.bls.gov/bls/proghome.htm#employment